1. Field of the Invention
The present invention relates to a chip antenna, and more particularly, to a chip antenna having a new mono-pole structure which enables achievement of low and broadband resonance frequency without increasing volume.
2. Description of the Related Art
In general, miniaturization in mobile telecommunication terminals has brought necessity of miniaturization of chip antennas as well. The miniaturized chip antenna is manufactured by using a single dielectric block or depositing plural dielectric sheets to form a dielectric block and then forming conductor patterns constituting radiation element on the dielectric block.
A chip antenna installed in a Bluetooth or a Wireless Local Area Network (WLAN) mobile telecommunication terminal requires relatively low frequency band, and thus has longer conductor patterns constituting a radiation element to obtain a sufficient length of electric resonance, which makes the chip antenna more difficult to be miniaturized.
In order to solve such a problem, Korean Patent Publication No. 423395 (assigned to Samsung Electro-Mechanics, published on Mar. 5, 2004) discloses miniaturization of a chip antenna which uses conductive patterns having bent parts. As shown in FIG. 1, the chip antenna according to the above literature includes a rectangular parallelepiped dielectric block 11 having upper and lower surfaces. And conductor patterns 12a and 12b are bent in a regular shape and formed on upper and lower surfaces of the dielectric block 11. In addition, the conductor patterns 12a and 12b are connected with side conductor patterns 15 to form a single radiation line wound in a spiral.
Such conductor pattern structure has an advantage in that it is integrated on a surface of a dielectric block of a small volume, allowing obtainment of sufficient length of electric resonance. Therefore, the chip antenna can be further miniaturized from the existing one designed to achieve the same desired resonance frequency.
However, mobile telecommunication terminals are further miniaturized recently and thus a chip antenna with even lower resonance frequency in a same volume is required. Using a dielectric block of 3×2×1.2 (mm), the chip antenna disclosed in the above document is able to manufacture a sufficiently long radiation line to achieve a resonance frequency of the Bluetooth band (3.55 GHz) but is not able to achieve a resonance frequency of the WLAN band (2.45 GHz). In order to achieve even lower frequency, large size of the chip antennas is inevitable.
In the meantime, it is desirable for the chip antenna to achieve resonance frequency band as wide as possible to maintain sending and receiving capabilities in the changing external conditions, but there is a limitation as to maintaining a miniaturized structure and achieving wide resonance frequency band as desired at the same time.